Public Law (P.L.) 94-171, enacted by Congress in December 1975, requires the Census Bureau to provide states the opportunity to identify the small area geography for which they need data in order to conduct legislative redistricting. The law also requires the U.S. Census Bureau to furnish tabulations of population to each state, including for those small areas the states have identified, within one year of Census day.
Since the first Census Redistricting Data Program, conducted as part of the 1980 census, the U.S. Census Bureau has included summaries for the major race groups specified by the Statistical Programs and Standards Office of the U.S. Office of Management and Budget (OMB) in Directive 15 (as issued in 1977 and revised in 1997). Originally, the tabulation groups included White, Black, American Indian/Alaska Native, and Asian/Pacific Islander, plus “some other race.” These race data were also cross-tabulated by Hispanic/Non-Hispanic origin. At the request of the state legislatures and the Department of Justice, for the 1990 Census Redistricting Data Program, voting age (18 years old and over) was added to the cross-tabulation of race and Hispanic origin. For the 2000 Census, these categories were revised to the current categories used today.
The 2020 Census Redistricting Data (P.L. 94-171) Summary Files in the Legacy Format were posted for FTP download, by state, on August 12, 2021 and released on data.census.gov with the full redistricting toolkit on September 16, 2021. Both releases contained the same data, only the format was different.
The summary file tables include:
The 2020 Census Redistricting Data (P.L. 94-171) Summary File data are available for all 50 states, the District of Columbia, and the Commonwealth of Puerto Rico through data.census.gov and FTP download (in the Legacy Format).
The 2020 Census State Redistricting Data (P.L. 94-171) Summary File Technical Documentation is available in English, and in Spanish specifically for Puerto Rico. The 2020 Census National Redistricting Data (P.L. 94-171) Summary File Technical Documentation is available in English only. Links to the Technical Documentation are provided below.
Legacy Format Support Materials are provided to help data users work with the legacy format summary files. These materials include header records for each of the data segments in the summary file, Microsoft Access shells, an instructional guide and video tutorial that provide step-by-step instructions on how to download the legacy format data and import the data into the Microsoft Access Shells, and SAS and R statistical software import scripts. Links to these support materials are provided below.
The Census Bureau published a Federal Register Notice on the Final 2020 Census Residence Criteria and Residence Situations on February 8, 2018. In the Notice, the Census Bureau stated we will continue the practice of counting prisoners at the correctional facility, to ensure that the concept of usual residence is interpreted and applied consistent with the intent of the Census Act of 1790. The Notice also stated the Census Bureau recognizes that some states have decided, or may decide in the future, to ‘move’ their group quarters (GQ) population (e.g. student, military, and prisoner population) to an alternate address for the purpose of redistricting. To assist those states, the Census Bureau is offering the use of a geocoding service. This service was updated with 2020 Census geographic data in January 2021, to assist states with their goals of reallocating GQ population for legislative redistricting.
What to Consider if You Find an Unexpected Census Result
Overall, 2020 Census redistricting data are comparable to population benchmarks. If you find a result you did not expect, there are several things to consider.
Disclosure Avoidance for the 2020 Census: An Introduction
In this handbook, the U.S. Census Bureau’s Disclosure Avoidance System is described in the context of the 2020 Census Redistricting Data Summary File.
Strength in Numbers: A Guide to the 2020 Census Redistricting Data
This brochure explains where census numbers come from and the role they have in the way states redraw the boundaries of their legislative districts.
2020 Census Redistricting Data Product Frequently Asked Questions
Information on plans to release the 2020 Census P.L. 94-171 Redistricting Data Summary Files.
Using Demographic Benchmarks to Help Evaluate 2020 Census Results
One of the primary methods of evaluating the quality of a census is comparing the results to other population benchmarks.
The Census Geocoder - Group Quarters Assistance
People living in group quarters, such as nursing homes, military barracks, and college/university student housing, are among the unique populations counted in the 2020 Census.
Improvements to the 2020 Census Race and Hispanic Origin Question Designs, Data Processing, and Coding Procedures
This blog discusses how we improved the census questions on race and Hispanic origin, also known as ethnicity, between 2010 and 2020.
How We Complete the Census When Demographic and Housing Characteristics Are Missing
Although we strive to obtain all demographic and housing data from every individual in the census, missing data are part of every census process.
Resources Available to Prepare for the 2020 Census Redistricting Data Release
In a few weeks, we’ll release the 2020 Census redistricting data in our legacy summary file format. And a few weeks after that, we’ll release the same data in an easier-to-use format.
Redistricting Data: What to Expect and When
Since releasing the apportionment results in April, we’ve had several teams working hard on the next set of 2020 Census data — the redistricting data.
Datos para la redistribución legislativa: qué esperar y cuándo
Hemos tenido varios equipos trabajando arduamente en el próximo conjunto de datos del Censo 2020 : los datos de redistritación.
Protecting the Confidentiality of 2020 Census Redistricting Data
By law, we must ensure that we don’t release information that could identify your information in the statistics we publish.
Comparing Differential Privacy With Older Disclosure Avoidance Methods
Differential privacy, first developed in 2006, is a framework for measuring the precise disclosure risk associated with each release of confidential data.
Differential Privacy and the 2020 Census
Differential privacy is a mathematical approach inspired by modern cryptography principles that disguises an individual’s identity in published data.
Бюро переписи предоставляет информацию о разрешении вопросов подсчета
Бюро переписи населения США отправило государственным должностным лицам информацию об операции по разрешению вопросов подсчета в рамках Переписи населения 2020.
In declarations filed in the case of Ohio v. Raimondo, the U.S. Census Bureau made clear that we could provide a legacy format redistricting data summary file to all states by mid-to-late August 2021, now realized as August 12. We also met our commitment to provide the full redistricting data toolkit by Sept. 30, 2021, with delivery on Sept. 16, 2021.